Conductive line system and process

ABSTRACT

A system and method for providing a conductive line is provided. In an embodiment the conductive line is formed by forming two passivation layers, wherein each passivation layer is independently patterned. Once formed, a seed layer is deposited into the two passivation layers, and a conductive material is deposited to fill and overfill the patterns within the two passivation layers. A planarization process such as a chemical mechanical polish may then be utilized in order to remove excess conductive material and form the conductive lines within the two passivation layers.

This application claims priority to U.S. Provisional Application No.61/789,593, filed on Mar. 15, 2013, and entitled “Conductive Line Systemand Process,” which application is incorporated herein by reference.

BACKGROUND

Generally, active devices and passive devices are formed on and in asemiconductor substrate. Once formed, these active devices and passivedevices may be connected to each other and to external devices using aseries of conductive and insulative layers. These layers may help tointerconnect the various active devices and passive devices as well asprovide an electrical connection to external devices through, forexample, a contact pad. To provide additional flexibility to designs, apost-passivation interconnect may be utilized to position externalcontacts where desired after the contact pad has been formed and afterpassivation layers have been formed over the contact pad.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the embodiments, and the advantagesthereof, reference is now made to the following descriptions taken inconjunction with the accompanying drawings, in which:

FIG. 1 illustrates a cross-sectional view of a substrate with a secondpassivation layer over a contact pad in accordance with an embodiment;

FIGS. 2A-2B illustrate a patterning and development of the secondpassivation layer in accordance with an embodiment;

FIG. 3 illustrates a placement of a third passivation layer inaccordance with an embodiment;

FIG. 4 illustrates a patterning and development of the third passivationlayer in accordance with an embodiment;

FIG. 5 illustrates a curing process in accordance with an embodiment;

FIG. 6 illustrates a formation of a seed layer in accordance with anembodiment;

FIG. 7 illustrates a formation of a conductive material in accordancewith an embodiment;

FIG. 8 illustrates a planarization process in accordance with anembodiment; and

FIG. 9 illustrates an external contact and buffer layer in accordancewith an embodiment.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the present embodiments are discussed in detailbelow. It should be appreciated, however, that the embodiments providemany applicable inventive concepts that can be embodied in a widevariety of specific contexts. The embodiments discussed are merelyillustrative of specific ways to make and use the embodiments, and donot limit the scope of the embodiments.

The embodiments will be described with respect to embodiments in aspecific context, namely an interconnect structure formed afterpassivation using a process similar to a dual damascene process. Theembodiments may also be applied, however, to other interconnectstructures.

With reference now to FIG. 1, there is shown a portion of asemiconductor die 100 including a semiconductor substrate 101 withmetallization layers 103, a contact pad 105, a first passivation layer107, and a second passivation layer 109. The semiconductor substrate 101may comprise bulk silicon, doped or undoped, or an active layer of asilicon-on-insulator (SOI) substrate. Generally, an SOI substratecomprises a layer of a semiconductor material such as silicon,germanium, silicon germanium, SOI, silicon germanium on insulator(SGOI), or combinations thereof. Other substrates that may be usedinclude multi-layered substrates, gradient substrates, or hybridorientation substrates.

Active devices (not shown) may be formed on the semiconductor substrate101. As one of ordinary skill in the art will recognize, a wide varietyof active devices such as capacitors, resistors, inductors and the likemay be used to generate the desired structural and functionalrequirements of the design for the semiconductor die 100. The activedevices may be formed using any suitable methods either within or elseon the surface of the semiconductor substrate 101.

The metallization layers 103 are formed over the semiconductor substrate101 and the active devices and are designed to connect the variousactive devices to form functional circuitry. While illustrated in FIG. 1as a single layer, the metallization layers 103 may be formed ofalternating layers of dielectric (e.g., low-k dielectric material) andconductive material (e.g., copper) and may be formed through anysuitable process (such as deposition, damascene, dual damascene, etc.).In an embodiment there may be four layers of metallization separatedfrom the semiconductor substrate 101 by at least one interlayerdielectric layer (ILD), but the precise number of metallization layers103 is dependent upon the design of the semiconductor die 100.

The contact pad 105 may be formed over and in electrical contact withthe metallization layers 103. The contact pad 105 may comprise aluminum,but other materials, such as copper, may alternatively be used. Thecontact pad 105 may be formed using a deposition process, such assputtering, to form a layer of material (not shown) and portions of thelayer of material may then be removed through a suitable process (suchas photolithographic masking and etching) to form the contact pad 105.However, any other suitable process may be utilized to form the contactpad 105. The contact pad 105 may be formed to have a thickness ofbetween about 0.5 μm and about 4 μm, such as about 1.45 μm.

The first passivation layer 107 may be formed on the semiconductorsubstrate 101 over the metallization layers 103 and the contact pad 105.The first passivation layer 107 may be made of one or more suitabledielectric materials such as silicon oxide, silicon nitride, low-kdielectrics such as carbon doped oxides, extremely low-k dielectricssuch as porous carbon doped silicon dioxide, combinations of these, orthe like. The first passivation layer 107 may be formed through aprocess such as chemical vapor deposition (CVD), although any suitableprocess may be utilized, and may have a thickness between about 0.5 μmand about 5 μm, such as about 9.25 KÅ.

After the first passivation layer 107 has been formed, an opening may bemade through the first passivation layer 107 by removing portions of thefirst passivation layer 107 to expose at least a portion of theunderlying contact pad 105. The opening allows for contact between thecontact pad 105 and a PPI 803 (not illustrated in FIG. 1 but illustratedand discussed further below with respect to FIG. 8). The opening may beformed using a suitable photolithographic mask and etching process,although any suitable process to expose portions of the contact pad 105may be used.

The second passivation layer 109 may be formed over the firstpassivation layer 107 and in the opening to contact the contact pad 105.In an embodiment the second passivation layer 109 may comprise, forexample, a negative tone photosensitive composition such as a negativetone photosensitive polyimide composition. For example, such a negativetone photosensitive polyimide composition in the second passivationlayer 109 may comprise a negative tone photosensitive polyimide resinalong with a photoactive components (PACs) placed into a negative tonephotosensitive polyimide solvent.

In an embodiment the negative tone photosensitive polyimide resin maycomprise a polymer that is made up of monomers of the following formula:

where X is a tetravalent organic group derived from alicyclictetracarboxylic acid dianhydrides having 3 to 30 carbon atoms; A₁ is anoxygen atom or an NH group; and Y is a di-valent organic group derivedfrom aliphatic, alicyclic, or non-conjugated aromatic diamines withcarbon atoms between 3 and 30, wherein side chains have one or moreethylenically unsaturated, cross-linkable bonds. R₁ is a hydrogen atomor an organic group having 1 to 20 carbon atoms including one or moreethylenically unsaturated bonds or, alternatively, is a group comprisinga photopolymerizable olefin double bond. In a particular embodiment R₁may comprise the following structure:

where R₂ is an aryl residue such as C₂H₃ or C₃H₅, R₃ is a residue withat least one photopolymerizable olefin double bond, G is a divalentaliphatic or aromatic group, which may be unsubstituted or has one ormore hydroxyl substituents, A₂ is an oxygen atom or an NR group, inwhich R indicates a hydrogen atom or a C₁-C₄ alkyl group, A₃ is anoxygen atom or an NR group, in which R indicates a hydrogen atom or aC₁-C₄ alkyl group, y is 0 or 1 and z is 0 or 1.

Additionally, while the negative tone photosensitive polyimide resin maybe one of the embodiments as described above, the negative tonephotosensitive polyimide resin is not intended to be limited to only thespecific examples described herein. Rather, any suitable negative tonephotosensitive polyimide resin may alternatively be utilized, and allsuch photosensitive polyimide resins are fully intended to be includedwithin the scope of the embodiments.

The PACs may be photoactive components such as photoacid generators,photobase generators, free-radical generators, or the like, and the PACsmay be positive-acting or negative-acting. In an embodiment in which thePACs are a photoacid generator, the PACs may comprise halogenatedtriazines, onium salts, diazonium salts, aromatic diazonium salts,phosphonium salts, sulfonium salts, iodonium salts, imide sulfonate,oxime sulfonate, disulfone, o-nitrobenzylsulfonate, sulfonated esters,halogenerated sulfonyloxy dicarboximides, diazodisulfones,α-cyanooxyamine-sulfonates, imidesulfonates, ketodiazosulfones,sulfonyldiazoesters, 1,2-di(arylsulfonyl)hydrazines, nitrobenzyl esters,and the s-triazine derivatives, suitable combinations of these, and thelike.

Specific examples of photoacid generators that may be used includeα.-(trifluoromethylsulfonyloxy)-bicyclo[2.2.1]hept-5-ene-2,3-dicarbo-ximide(MDT), N-hydroxy-naphthalimide (DDSN), benzoin tosylate,t-butylphenyl-α-(p-toluenesulfonyloxy)-acetate andt-butyl-α-(p-toluenesulfonyloxy)-acetate, triarylsulfonium anddiaryliodonium hexafluoroantimonates, hexafluoroarsenates,trifluoromethanesulfonates, iodonium perfluorooctanesulfonate,N-camphorsulfonyloxynaphthalimide,N-pentafluorophenylsulfonyloxynaphthalimide, ionic iodonium sulfonatessuch as diaryl iodonium (alkyl or aryl) sulfonate andbis-(di-t-butylphenyl)iodonium camphanylsulfonate,perfluoroalkanesulfonates such as perfluoropentanesulfonate,perfluorooctanesulfonate, perfluoromethanesulfonate, aryl (e.g., phenylor benzyl) triflates such as triphenylsulfonium triflate orbis-(t-butylphenyl)iodonium triflate; pyrogallol derivatives (e.g.,trimesylate of pyrogallol), trifluoromethanesulfonate esters ofhydroxyimides, α,α′-bis-sulfonyl-diazomethanes, sulfonate esters ofnitro-substituted benzyl alcohols, naphthoquinone-4-diazides, alkyldisulfones, and the like.

In an embodiment in which the PACs are a free-radical generator, thePACs may comprise n-phenylglycine, aromatic ketones such asbenzophenone, N,N′-tetramethyl-4,4′-diaminobenzophenone,N,N′-tetraethyl-4,4′-diaminobenzophenone,4-methoxy-4′-dimethylaminobenzo-phenone,3,3′-dimethyl-4-methoxybenzophenone,p,p′-bis(dimethylamino)benzo-phenone,p,p′-bis(diethylamino)-benzophenone, anthraquinone,2-ethylanthraquinone, naphthaquinone and phenanthraquinone, benzoinssuch as benzoin, benzoinmethylether, benzomethylether,benzoinisopropylether, benzoin-n-butylether, benzoin-phenylether,methylbenzoin and ethybenzoin, benzyl derivatives such as dibenzyl,benzyldiphenyldisulfide and benzyldimethylketal, acridine derivativessuch as 9-phenylacridine and 1,7-bis(9-acridinyl)heptane, thioxanthonessuch as 2-chlorothioxanthone, 2-methylthioxanthone,2,4-diethylthioxanthone, 2,4-dimethylthioxanthone and2-isopropylthioxanthone, acetophenones such as 1,1-dichloroacetophenone,p-t-butyldichloro-acetophenone, 2,2-diethoxyacetophenone,2,2-dimethoxy-2-phenylacetophenone, and2,2-dichloro-4-phenoxyacetophenone, 2,4,5-triarylimidazole dimers suchas 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer,2-(o-chlorophenyl)-4,5-di-(m-methoxyphenyl imidazole dimer,2-(o-fluorophenyl)-4,5-diphenylimidazole dimer,2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer,2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer,2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer,2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer and2-(p-methylmercaptophenyl)-4,5-diphenylimidazole dimmer, suitablecombinations of these, or the like.

In an embodiment in which the PACs are a photobase generator, the PACsmay comprise quaternary ammonium dithiocarbamates, α aminoketones,oxime-urethane containing molecules such as dibenzophenoneoximehexamethylene diurethan, ammonium tetraorganylborate salts, andN-(2-nitrobenzyloxycarbonyl)cyclic amines, suitable combinations ofthese, or the like. However, as one of ordinary skill in the art willrecognize, the chemical compounds listed herein are merely intended asillustrated examples of the PACs and are not intended to limit theembodiments to only those PACs specifically described. Rather, anysuitable PAC may alternatively be utilized, and all such PACs are fullyintended to be included within the scope of the present embodiments.

In an embodiment the negative tone photosensitive polyimide solvent maybe an organic solvent, and may comprise any suitable solvent such asketones, alcohols, polyalcohols, ethers, glycol ethers, cyclic ethers,aromatic hydrocarbons, esters, propionates, lactates, lactic esters,alkylene glycol monoalkyl ethers, alkyl lactates, alkylalkoxypropionates, cyclic lactones, monoketone compounds that contain aring, alkylene carbonates, alkyl alkoxyacetate, alkyl pyruvates,ethylene glycol alkyl ether acetates, diethylene glycols, propyleneglycol alkyl ether acetates, alkylene glycol alkyl ether esters,alkylene glycol monoalkyl esters, or the like.

Specific examples of materials that may be used as the negative tonephotosensitive polyimide solvent for the negative tone photosensitivepolyimide composition include acetone, methanol, ethanol, toluene,xylene, 4-hydroxy-4-methyl-2-pentatone, tetrahydrofuran, methyl ethylketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethyleneglycol, ethylene glycol monoacetate, ethylene glycol dimethyl ether,ethylene glycol methylethyl ether, ethylene glycol monoethyl ether,methyl celluslve acetate, ethyl cellosolve acetate, diethylene glycol,diethylene glycol monoacetate, diethylene glycol monomethyl ether,diethylene glycol diethyl ether, diethylene glycol dimethyl ether,diethylene glycol ethylmethyl ether, diethylene glycol monoethyl ether,diethylene glycol monobutyl ether, ethyl 2-hydroxypropionate, methyl2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethylethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanate,methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butylacetate, methyl lactate and ethyl lactate, propylene glycol, propyleneglycol monoacetate, propylene glycol monoethyl ether acetate, propyleneglycol monomethyl ether acetate, propylene glycol monopropyl methylether acetate, propylene glycol monobutyl ether acetate, propyleneglycol monobutyl ether acetate, propylene glycol monomethyl etherpropionate, propylene glycol monoethyl ether propionate, propyleneglycol methyl ether acetate, propylene glycol ethyl ether acetate,ethylene glycol monomethyl ether acetate, ethylene glycol monoethylether acetate, propylene glycol monomethyl ether, propylene glycolmonoethyl ether, propylene glycol monopropyl ether, propylene glycolmonobutyl ether, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, propyl lactate, and butyl lactate, ethyl3-ethoxypropionate, methyl 3-methoxypropionate, methyl3-ethoxypropionate, and ethyl 3-methoxypropionate, β-propiolactone,β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone,β-methyl-γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-octanoiclactone, α-hydroxy-γ-butyrolactone, 2-butanone, 3-methylbutanone,pinacolone, 2-pentanone, 3-pentanone, 4-methyl-2-pentanone,2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone,2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone,3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone,2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone,2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone,3-decanone, 4-decanone, 5-hexene-2-one, 3-pentene-2-one, cyclopentanone,2-methylcyclopentanone, 3-methylcyclopentanone,2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone,cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone,4-ethylcyclohexanone, 2,2-dimethylcyclohexanone,2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone,2-methylcycloheptanone, 3-methylcycloheptanone, pylene carbonate,vinylene carbonate, ethylene carbonate, and butylene carbonate,acetate-2-methoxyethyl, acetate-2-ethoxyethyl,acetate-2-(2-ethoxyethoxy)ethyl, acetate-3-methoxy-3-methylbutyl,acetate-1-methoxy-2-propyl, dipropylene glycol, monomethylether,monoethylether, monopropylether, monobutylehter, monophenylether,dipropylene glycol monoacetate, dioxane, ethyl lactate, methyl acetate,ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, propylpyruvate, methyl methoxypropionate, ethyl ethoxypropionate,n-methylpyrrolidone (NMP), 2-methoxyethyl ether (diglyme), ethyleneglycol monom-ethyl ether, propylene glycol monomethyl ether; methylproponiate, ethyl proponiate and ethyl ethoxy proponiate, methylethylketone, cyclohexanone, 2-heptanone, carbon dioxide, cyclopentatone,cyclohexanone, ethyl 3-ethocypropionate, propylene glycol methyl etheracetate (PGMEA), methylene cellosolve, butyl acetate, and2-ethoxyethanol, N-methylformamide, N,N-dimethylformamide,N-methylformanilide, N-methylacetamide, N,N-dimethylacetamide,N-methylpyrrolidone, dimethylsulfoxide, benzyl ethyl ether, dihexylether, acetonylacetone, isophorone, caproic acid, caprylic acid,1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate,diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate,propylene carbonate, phenyl cellosolve acetate, or the like.

In an embodiment the negative tone photosensitive polyimide resin andthe PACs, along with any desired additives or other agents, are added tothe negative tone photosensitive polyimide solvent for application. Forexample, the negative tone photosensitive polyimide resin may have aconcentration of between about 5% and about 50%, such as about 25%,while the PACs may have a concentration of between about 0.1% and about20%, such as about 5%. Once added, the mixture is then mixed in order toachieve an even composition throughout the negative tone photosensitivepolyimide composition in order to ensure that there are no defectscaused by an uneven mixing or non-constant composition. Once mixedtogether, the negative tone photosensitive polyimide composition mayeither be stored prior to its usage or else used immediately.

Once ready, the second passivation layer 109 may be utilized byinitially applying the negative tone photosensitive polyimidecomposition onto the first passivation layer 107. The second passivationlayer 109 may be applied to the first passivation layer 107 so that thesecond passivation layer 109 coats an upper exposed surface of the firstpassivation layer 107, and may be applied using a process such as aspin-on coating process, a dip coating method, an air-knife coatingmethod, a curtain coating method, a wire-bar coating method, a gravurecoating method, a lamination method, an extrusion coating method,combinations of these, or the like. The second passivation layer 109 maybe placed to a thickness of between about 1 μm to about 40 μm.

FIGS. 2A-2B illustrate a patterning and development of the secondpassivation layer 109. Once applied, the second passivation layer 109may be exposed to form an exposed region 201 and an unexposed region 203within the second passivation layer 109. In an embodiment the exposuremay be initiated by placing the substrate 101 and the second passivationlayer 109 into an imaging device 200 for exposure. The imaging device200 may comprise a support plate 204, a energy source 207, a patternedmask 209 between the support plate 204 and the energy source 207, andoptics 213. In an embodiment the support plate 204 is a surface to whichthe semiconductor device 100 and the second passivation layer 109 may beplaced or attached to and which provides support and control to thesubstrate 101 during exposure of the second passivation layer 109.Additionally, the support plate 204 may be movable along one or moreaxes, as well as providing any desired heating or cooling to thesubstrate 101 and second passivation layer 109 in order to preventtemperature gradients from affecting the exposure process.

In an embodiment the energy source 207 supplies energy 211 such as lightto the second passivation layer 109 in order to induce a reaction of thePACs, which in turn reacts with, e.g., the negative tone photosensitivepolyimide resin to chemically alter those portions of the secondpassivation layer 109 to which the energy 211 impinges. In an embodimentthe energy 211 may be electromagnetic radiation, such as g-rays (with awavelength of about 436 nm), i-rays (with a wavelength of about 365 nm),ultraviolet radiation, far ultraviolet radiation, x-rays, electronbeams, or the like. The energy source 207 may be a source of theelectromagnetic radiation, and may be a KrF excimer laser light (with awavelength of 248 nm), an ArF excimer laser light (with a wavelength of193 nm), a F₂ excimer laser light (with a wavelength of 157 nm), or thelike, although any other suitable source of energy 211, such as mercuryvapor lamps, xenon lamps, carbon arc lamps or the like, mayalternatively be utilized.

The patterned mask 209 is located between the energy source 207 and thesecond passivation layer 109 in order to block portions of the energy211 to form a patterned energy 215 prior to the energy 211 actuallyimpinging upon the second passivation layer 109. In an embodiment thepatterned mask 209 may comprise a series of layers (e.g., substrate,absorbance layers, anti-reflective coating layers, shielding layers,etc.) to reflect, absorb, or otherwise block portions of the energy 211from reaching those portions of the second passivation layer 109 whichare not desired to be illuminated. The desired pattern may be formed inthe patterned mask 209 by forming openings through the patterned mask209 in the desired shape of illumination.

Optics (represented in FIG. 2A by the trapezoid labeled 213) may be usedto concentrate, expand, reflect, or otherwise control the energy 211 asit leaves the energy source 207, is patterned by the patterned mask 209,and is directed towards the second passivation layer 109. In anembodiment the optics 213 comprise one or more lenses, mirrors, filters,combinations of these, or the like to control the energy 211 along itspath. Additionally, while the optics 213 are illustrated in FIG. 2A asbeing between the patterned mask 209 and the second passivation layer109, elements of the optics 213 (e.g., individual lenses, mirrors, etc.)may also be located at any location between the energy source 207 (wherethe energy 211 is generated) and the second passivation layer 109.

In an embodiment the semiconductor device 100 with the secondpassivation layer 109 is placed on the support plate 204. Once thepattern has been aligned to the semiconductor device 100, the energysource 207 generates the desired energy 211 (e.g., light) which passesthrough the patterned mask 209 and the optics 213 on its way to thesecond passivation layer 109. The patterned energy 215 impinging uponportions of the second passivation layer 109 induces a reaction of thePACs within the second passivation layer 109. The chemical reactionproducts of the PACs' absorption of the patterned energy 215 (e.g.,acids/bases/free radicals) then reacts, chemically altering the secondpassivation layer 109 in those portions that were illuminated throughthe patterned mask 209.

Optionally, the exposure of the second passivation layer 109 may occurusing an immersion lithography technique. In such a technique animmersion medium (not individually illustrated in FIG. 2A) may be placedbetween the imaging device 200 (and particularly between a final lens ofthe optics 213) and the second passivation layer 109. With thisimmersion medium in place, the second passivation layer 109 may bepatterned with the patterned energy 215 passing through the immersionmedium.

In this embodiment a protective layer (also not individually illustratedin FIG. 2A) may be formed over the second passivation layer 109 in orderto prevent the immersion medium from coming into direct contact with thesecond passivation layer 109 and leaching or otherwise adverselyaffecting the second passivation layer 109. In an embodiment theprotective layer is insoluble within the immersion medium such that theimmersion medium will not dissolve it and is immiscible in the secondpassivation layer 109 such that the protective layer will not adverselyaffect the second passivation layer 109. Additionally, the protectivelayer is transparent so that the patterned energy 215 may pass throughthe protective layer without hindrance.

In an embodiment the protective layer comprises a protective layer resinwithin a protective layer solvent. The material used for the protectivelayer solvent is, at least in part, dependent upon the components chosenfor the second passivation layer 109, as the protective layer solventshould not dissolve the materials of the second passivation layer 109 soas to avoid degradation of the second passivation layer 109 duringapplication and use of the protective layer. In an embodiment theprotective layer solvent includes alcohol solvents, fluorinatedsolvents, and hydrocarbon solvents.

Specific examples of materials that may be utilized for the protectivelayer solvent include methanol, ethanol, 1-propanol, isopropanol,n-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol,3-methyl-1-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol,2-pentanol, 3-pentanol, n-hexanol, cyclohecanol, 1-hexanol, 1-heptanol,1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol,3-octanol, 4-octanol, 2-methyl-2-butanol, 3-methyl-1-butanol,3-methyl-2-butanol, 2-methyl-1-butanol, 2-methyl-1-pentanol,2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol,3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol,4-methyl-2-pentanol, 2,2,3,3,4,4-hexafluoro-1-butanol,2,2,3,3,4,4,5,5-octafluoro-1-pentanol,2,2,3,3,4,4,5,5,6,6-decafluoro-1-hexanol,2,2,3,3,4,4-hexafluoro-1,5-pentanediol,2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol,2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-1,8-diol, 2-fluoroanisole,2,3-difluoroanisole, perfluorohexane, perfluoroheptane,perfluoro-2-pentanone, perfluoro-2-butyltetrahydrofuran,perfluorotetrahydrofuran, perfluorotributylamine,perfluorotetrapentylamine, toluene, xylene and anisole, and aliphatichydrocarbon solvents, such as n-heptane, n-nonane, n-octane, n-decane,2-methylheptane, 3-methylheptane, 3,3-dimethylhexane,2,3,4-trimethylpentane, combinations of these, or the like.

The protective layer resin may comprise a protective layer repeatingunit. In an embodiment the protective layer repeating unit may be anacrylic resin with a repeating hydrocarbon structure having a carboxylgroup, an alicyclic structure, an alkyl group having one to five carbonatoms, a phenol group, or a fluorine atom-containing group. Specificexamples of the alicyclic structure include a cyclohexyl group, anadamantyl group, a norbornyl group, a isobornyl group, a tricyclodecylgroup, a tetracyclododecyl group, and the like. Specific examples of thealkyl group include an n-butyl group, an isobutyl group, or the like.However, any suitable protective layer resin may alternatively beutilized.

The protective layer composition may also include additional additivesto assist in such things as adhesion, surface leveling, coating, and thelike. For example, the protective layer composition may further comprisea protective layer surfactant, although other additives may also beadded, and all such additions are fully intended to be included withinthe scope of the embodiment. In an embodiment the protective layersurfactant may be an alkyl cationic surfactant, an amide-type quaternarycationic surfactant, an ester-type quaternary cationic surfactant, anamine oxide surfactant, a betaine surfactant, an alkoxylate surfactant,a fatty acid ester surfactant, an amide surfactant, an alcoholsurfactant, an ethylenediamine surfactant, or a fluorine- and/orsilicon-containing surfactant.

Specific examples of materials that may be used for the protective layersurfactant include polyoxyethylene alkyl ethers, such as polyoxyethylenelauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl etherand polyoxyethylene oleyl ether; polyoxyethylene alkyl aryl ethers, suchas polyoxyethylene octyl phenol ether and polyoxyethylene nonyl phenolether; polyoxyethylene-polyooxypropylene block copolymers; sorbitanfatty acid esters, such as sorbitan monolaurate, sorbitan monopalmitate,sorbitan monostearate, sorbitan monooleate, sorbitan trioleate andsorbitan tristearate; and polyoxyethylene sorbitan monolaurate,polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitanmonostearate, polyoxyethylene sorbitan trioleate and polyoxyethylenesorbitan tristearate.

Prior to application of the protective layer onto the second passivationlayer 109, the protective layer resin and desired additives are firstadded to the protective layer solvent to form a protective layercomposition. The protective layer solvent is then mixed to ensure thatthe protective layer composition has a consistent concentrationthroughout the protective layer composition.

Once the protective layer composition is ready for application, theprotective layer composition may be applied over the second passivationlayer 109. In an embodiment the application may be performed using aprocess such as a spin-on coating process, a dip coating method, anair-knife coating method, a curtain coating method, a wire-bar coatingmethod, a gravure coating method, a lamination method, an extrusioncoating method, combinations of these, or the like. In an embodiment thesecond passivation layer 109 may be applied such that it has a thicknessover the surface of the second passivation layer 109 of about 100 nm.

After the protective layer composition has been applied to the secondpassivation layer 109, a protective layer pre-bake may be performed inorder to remove the protective layer solvent. In an embodiment theprotective layer pre-bake may be performed at a temperature suitable toevaporate the protective layer solvent, such as between about 40° C. and150° C., although the precise temperature depends upon the materialschosen for the protective layer composition. The protective layerpre-bake is performed for a time sufficient to cure and dry theprotective layer composition, such as between about 10 seconds to about5 minutes, such as about 90 seconds.

Once the protective layer has been placed over the second passivationlayer 109, the semiconductor device 100 with the second passivationlayer 109 and the protective layer are placed on the support plate 204,and the immersion medium may be placed between the protective layer andthe optics 213. In an embodiment the immersion medium is a liquid havinga refractive index greater than that of the surrounding atmosphere, suchas having a refractive index greater than 1. Examples of the immersionmedium may include water, oil, glycerine, glycerol, cycloalkanols, orthe like, although any suitable medium may alternatively be utilized.

The placement of the immersion medium between the protective layer andthe optics 213 may be done using, e.g., an air knife method, wherebyfresh immersion medium is applied to a region between the protectivelayer and the optics 213 and controlled using pressurized gas directedtowards the protective layer to form a barrier and keep the immersionmedium from spreading. In this embodiment the immersion medium may beapplied, used, and removed from the protective layer for recycling sothat there is fresh immersion medium used for the actual imagingprocess.

However, the air knife method described above is not the only method bywhich the second passivation layer 109 may be exposed using an immersionmethod. Any other suitable method for imaging the second passivationlayer 109 using an immersion medium, such as immersing the entiresubstrate 101 along with the second passivation layer 109 and theprotective layer, using solid barriers instead of gaseous barriers, orusing an immersion medium without a protective layer, may also beutilized. Any suitable method for exposing the second passivation layer109 through the immersion medium may be used, and all such methods arefully intended to be included within the scope of the embodiments.

FIG. 2B illustrates a development of the second passivation layer 109with the use of a developer after the second passivation layer 109 hasbeen exposed. After the second passivation layer 109 has been exposed,the second passivation layer 109 may be developed using a firstdeveloper. In an embodiment in which the second passivation layer 109 isthe negative tone photosensitive polyimide, the first developer may be abasic aqueous solution to remove those portions of the secondpassivation layer 109 which were unexposed to the patterned energy 215.Such basic aqueous solutions may include tetra methyl ammonium hydroxide(TMAH), tetra butyl ammonium hydroxide, sodium hydroxide, potassiumhydroxide, sodium carbonate, sodium bicarbonate, sodium silicate, sodiummetasilicate, aqueous ammonia, monomethylamine, dimethylamine,trimethylamine, monoethylamine, diethylamine, triethylamine,monoisopropylamine, diisopropylamine, triisopropylamine, monobutylamine,dibutylamine, monoethanolamine, diethanolamine, triethanolamine,dimethylaminoethanol, diethylaminoethanol, potassium metasilicate,sodium carbonate, tetraethylammonium hydroxide, combinations of these,or the like.

In an embodiment in which immersion lithography is utilized to exposethe second passivation layer 109 and a protective layer is utilized toprotect the second passivation layer 109 from the immersion medium, thedeveloper may be chosen to remove not only those portions of the secondpassivation layer 109 that are desired to be removed, but may also bechosen to remove the protective layer in the same development step.Alternatively, the protective layer may be removed in a separateprocess, such as by a separate solvent from the developer or even anetching process to remove the protective layer from the secondpassivation layer 109 prior to development.

The first developer may be applied to the second passivation layer 109using, e.g., a spin-on process. In this process the first developer isapplied to the second passivation layer 109 from above the secondpassivation layer 109 while the semiconductor device 100 (and the secondpassivation layer 109) is rotated. In an embodiment the first developermay be at a temperature of between about 10° C. and about 80° C., suchas about 50° C., and the development may continue for between about 1minute to about 60 minutes, such as about 30 minutes.

However, while the spin-on method described herein is one suitablemethod for developing the second passivation layer 109 after exposure,it is intended to be illustrative and is not intended to limit theembodiments. Rather, any suitable method for development, including dipprocesses, puddle processes, spray-on processes, combinations of these,or the like, may alternatively be used. All such development processesare fully intended to be included within the scope of the embodiments.

FIG. 2B illustrates a cross-section of the development process in anembodiment in which the first developer is used to remove the unexposedregions of the second passivation layer 109. The developer is applied tothe second passivation layer 109 and dissolves the unexposed portion 205of the second passivation layer 109. This dissolving and removing of theunexposed portion 205 of the second passivation layer 109 leaves behinda first opening 217 within the second passivation layer 109 thatpatterns the second passivation layer 109 in the shape of the patternedenergy 215, thereby transferring the pattern of the patterned mask 209to the second passivation layer 109. In an embodiment the first opening217 may have a width of between about 2 μm to about 300 μm, such asabout 5 μm to about 300 μm, and may be any desired shape such as round,oval, or polygonal.

FIG. 3 illustrates the placement of a third passivation layer 301 overthe second passivation layer 109. In an embodiment the third passivationlayer 301 may be a positive tone composition such as a positive tonephotosensitive polyimide composition (instead of the negative tonephotosensitive polyimide composition described above with respect to thesecond passivation layer 109). For example, the positive tonephotosensitive polyimide composition may comprise a positive tonephotosensitive polyimide resin along with the PACs within a positivetone photosensitive polyimide solvent. In an embodiment the positivetone photosensitive polyimide resin may be a polymer with a repeatingunit represented by the following formula:

where Z is a tetravalent organic group derived from one or moretetracarboxylic acids, including3,4-dicarboxy-1,2,3,4-tetrahydro-6-tert-butyl-1-naphthalene succinicdianhydride (DTBDA), or derivatives thereof, a is from 1 to 150, b isfrom 1 to 400, Y₁ is a divalent organic group derived from a diamine, Y₂is a divalent aliphatic group or aromatic organic group derived from adiamine.

Specific examples of Y₁ include the following formulas:

Specific examples of Y₂ include aromatic diamines, such asp-phenylenediamine, m-phenylenediamine,2,4,6-trimethyl-1,3-phenylenediamine,2,3,5,6-tetramethyl-1,4-phenylenediamine, 4,4′-diaminodiphenyl ether,3,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether,4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenylmethane,3,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane,4,4′-methylene-bis(2-methylaniline),4,4′-methylene-bis(2,6-dimethylaniline),4,4′-methylene-bis(2,6-diethylaniline),4,4′-methylene-bis(2-isopropyl-6-methylaniline),4,4′-methylene-bis(2,6-diisopropylaniline), 4,4′-diaminodiphenylsulfone,3,3′-diaminodiphenylsulfone, benzidine, o-tolidine, m-tolidine,3,3′,5,5′-tetramethylbenzidine, 2,2′-bis(trifluoromethyl)benzidine,1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene,1,3-bis(3-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone,bis[4-(3-aminophenoxy)phenyl]sulfone,2,2-bis[4-(4-aminophenoxy)phenyl]propane, and2,2-bis[4-(3-aminophenoxy)phenyl]propane; aliphatic diamines, such as1,6-hexanediamine, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine,1,4-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane,4,4′-diaminodicyclohexylmethane, 4,4′-diaminobenzanilide,2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane,1,3-bis(3-aminopropyl)tetramethyldisiloxane,bis(p-aminophenoxy)dimethylsilane, diaminohexane, diaminododecane,1,3-bis(4-aminophenoxy)benzene,2,2-bis[4-(4-aminophenoxy)phenyl]propane,1,1-bis(4-aminophenoxyphenyl)cyclohexane,bis[4-(4-aminophenoxy)phenyl]sulfone, 1,3-bis(3-aminophenoxy)benzene,5-amino-1,3,3-trimethylcyclohexanemethylamine,4,4′-bis(4-aminophenoxy)biphenyl, 1,1-bis(4-aminophenyl)cyclohexane,.alpha.,.alpha.′-bis(4-aminophenyl)-1,4-diisopropylbenzene,1,3-bis(4-aminophenoxy)-2,2-dimethylpropane,1,3-bis(4-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)fluorine, and4,4′-diamino-3,3′-dimethyldicyclohexylmethane, combinations of these, orthe like.

In an embodiment the positive tone photosensitive polyimide solvent maybe an organic solvent, and may comprise any suitable solvent such asketones, alcohols, polyalcohols, ethers, glycol ethers, cyclic ethers,aromatic hydrocarbons, esters, propionates, lactates, lactic esters,alkylene glycol monoalkyl ethers, alkyl lactates, alkylalkoxypropionates, cyclic lactones, monoketone compounds that contain aring, alkylene carbonates, alkyl alkoxyacetate, alkyl pyruvates,ethylene glycol alkyl ether acetates, diethylene glycols, propyleneglycol alkyl ether acetates, alkylene glycol alkyl ether esters,alkylene glycol monoalkyl esters, or the like.

Specific examples of materials that may be used as the positive tonephotosensitive polyimide solvent for the positive tone photosensitivepolyimide composition include acetone, methanol, ethanol, toluene,xylene, 4-hydroxy-4-methyl-2-pentatone, tetrahydrofuran, methyl ethylketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethyleneglycol, ethylene glycol monoacetate, ethylene glycol dimethyl ether,ethylene glycol methylethyl ether, ethylene glycol monoethyl ether,methyl celluslve acetate, ethyl cellosolve acetate, diethylene glycol,diethylene glycol monoacetate, diethylene glycol monomethyl ether,diethylene glycol diethyl ether, diethylene glycol dimethyl ether,diethylene glycol ethylmethyl ether, diethylene glycol monoethyl ether,diethylene glycol monobutyl ether, ethyl 2-hydroxypropionate, methyl2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethylethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanate,methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butylacetate, methyl lactate and ethyl lactate, propylene glycol, propyleneglycol monoacetate, propylene glycol monoethyl ether acetate, propyleneglycol monomethyl ether acetate, propylene glycol monopropyl methylether acetate, propylene glycol monobutyl ether acetate, propyleneglycol monobutyl ether acetate, propylene glycol monomethyl etherpropionate, propylene glycol monoethyl ether propionate, propyleneglycol methyl ether adcetate, propylene glycol ethyl ether acetate,ethylene glycol monomethyl ether acetate, ethylene glycol monoethylether acetate, propylene glycol monomethyl ether, propylene glycolmonoethyl ether, propylene glycol monopropyl ether, propylene glycolmonobutyl ether, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, propyl lactate, and butyl lactate, ethyl3-ethoxypropionate, methyl 3-methoxypropionate, methyl3-ethoxypropionate, and ethyl 3-methoxypropionate, β-propiolactone,β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone,β-methyl-γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-octanoiclactone, α-hydroxy-γ-butyrolactone, 2-butanone, 3-methylbutanone,pinacolone, 2-pentanone, 3-pentanone, 4-methyl-2-pentanone,2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone,2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone,3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone,2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone,2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone,3-decanone, 4-decanone, 5-hexene-2-one, 3-pentene-2-one, cyclopentanone,2-methylcyclopentanone, 3-methylcyclopentanone,2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone,cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone,4-ethylcyclohexanone, 2,2-dimethylcyclohexanone,2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone,2-methylcycloheptanone, 3-methylcycloheptanone, pylene carbonate,vinylene carbonate, ethylene carbonate, and butylene carbonate,acetate-2-methoxyethyl, acetate-2-ethoxyethyl,acetate-2-(2-ethoxyethoxy)ethyl, acetate-3-methoxy-3-methylbutyl,acetate-1-methoxy-2-propyl, dipropylene glycol, monomethylether,monoethylether, monopropylether, monobutylehter, monophenylether,dipropylene glycol monoacetate, dioxane, ethyl lactate, methyl acetate,ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, propylpyruvate, methyl methoxypropionate, ethyl ethoxypropionate,n-methylpyrrolidone (NMP), 2-methoxyethyl ether (diglyme), ethyleneglycol monom-ethyl ether, propylene glycol monomethyl ether; methylproponiate, ethyl proponiate and ethyl ethoxy proponiate, methylethylketone, cyclohexanone, 2-heptanone, carbon dioxide, cyclopentatone,cyclohexanone, ethyl 3-ethocypropionate, propylene glycol methyl etheracetate (PGMEA), methylene cellosolve, butyl acetate, and2-ethoxyethanol, N-methylformamide, N,N-dimethylformamide,N-methylformanilide, N-methylacetamide, N,N-dimethylacetamide,N-methylpyrrolidone, dimethylsulfoxide, benzyl ethyl ether, dihexylether, acetonylacetone, isophorone, caproic acid, caprylic acid,1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate,diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate,propylene carbonate, phenyl cellosolve acetate, or the like.

In an embodiment the positive tone photosensitive polyimide resin isplaced into the positive tone photosensitive polyimide solvent alongwith the PACs and mixed to form the positive tone photosensitivepolyimide composition. For example, the positive tone photosensitivepolyimide resin may have a concentration of between about 5% and about50%, such as about 25%, while the PACs may have a concentration ofbetween about 0.1% and about 20%, such as about 5%. Once the positivetone photosensitive polyimide composition has been mixed to have aconstant composition throughout the mixture, the positive tonephotosensitive polyimide composition is applied to the secondpassivation layer 109 to a thickness of between about 1 μm to about 40μm. The application may be performed using, e.g. a spin-coating method,although any suitable method may alternatively be utilized.

FIG. 4 illustrates the patterning and development of the thirdpassivation layer 301. In an embodiment the third passivation layer 301may be patterned in order to form a second opening 401 and thirdopenings 403. The second opening 401 may be formed over and connected tothe first opening 217 in the second passivation layer 109 in order toexpose a portion of the contact pad 105. The third openings 403 may beformed to define the dimensions of routing for conductive lines to beformed within the third passivation layer 301.

To pattern the third passivation layer 301, the substrate 101 along withthe third passivation layer 301 may be placed into the imaging device200 (described above with respect to FIG. 2A) or a different imagingdevice (not illustrated), and the third passivation layer 301 may beexposed to the patterned energy source 215 to define regions within thethird passivation layer 301 for the second opening 401 and the thirdopenings 403. In an embodiment the second opening 401 and the thirdopenings 403 may have a width of between about 2 μm and about 300 μm,such as about 5 μm to about 300 μm. Additionally, the second opening 401and the third openings 403 may be any desired shape, such as round,oval, polygonal, or the like.

Once exposed, the third passivation layer 301 may be developed using asecond developer. In an embodiment the second developer may be a basicaqueous solution to remove those portions of the second passivationlayer 109 which were exposed to the patterned energy 215 and which havehad their solubility modified and changed through the chemicalreactions. Such basic aqueous solutions may include tetra methylammonium hydroxide (TMAH), tetra butyl ammonium hydroxide, sodiumhydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate,sodium silicate, sodium metasilicate, aqueous ammonia, monomethylamine,dimethylamine, trimethylamine, monoethylamine, diethylamine,triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine,monobutylamine, dibutylamine, monoethanolamine, diethanolamine,triethanolamine, dimethylaminoethanol, diethylaminoethanol, potassiummetasilicate, sodium carbonate, tetraethylammonium hydroxide,combinations of these, or the like.

The second developer may be applied to the third passivation layer 301using, e.g., a spin-on process. In this process the second developer isapplied to the third passivation layer 301 from above the thirdpassivation layer 301 while the semiconductor device 100 (and the thirdpassivation layer 301) is rotated. In an embodiment the second developermay be at a temperature of between about 10° C. and about 80° C., suchas about 50° C., and the development may continue for between about 1minute to about 60 minutes, such as about 30 minutes.

FIG. 5 illustrates that, once the third passivation layer 301 has beenpatterned and developed, the third passivation layer 301 and the secondpassivation layer 109 may be cured (represented in FIG. 5 by the wavylines labeled 501). In an embodiment the curing process 501 may beperformed by placing the substrate 101 along with the second passivationlayer 109 and the third passivation layer 301 onto, e.g., a hot plate orother type of heating apparatus, wherein the temperature of the secondpassivation layer 109 and the third passivation layer 301 may beincreased. In an embodiment the curing process may be performed at atemperature of 150° C. to about 400° C. for a time of between about 1hour to about 2 hours.

Additionally, after the curing process, a descum process may be utilizedin order to remove undesired residue or particles that may remain on thecontact pad 105, the second passivation layer 109, and the thirdpassivation layer 301 after the patterning, developments, and curingprocess. In an embodiment the descum process comprises exposing thecontact pad 105, the second passivation layer 109, and the thirdpassivation layer 301 to a plasma environment, such as an oxygen plasmaenvironment, in order to react and remove any undesired residue. In aparticular embodiment the descum process may be a reactive ion etchprocess.

FIG. 6 illustrates a formation of a seed layer 601. Once the secondpassivation layer 109 and the third passivation layer 301 have beenformed, the seed layer 601 may be formed within the first opening 217,the second opening 401, and the third openings 403. In an embodiment theseed layer 601 may be, e.g., a titanium copper alloy, although anysuitable material, such as copper, may alternatively be utilized. Theseed layer 601 may be formed through a suitable formation process suchas CVD or sputtering.

FIG. 7 illustrates a formation of conductive material 701 on the seedlayer 601, filling and overfilling the first opening 217, the secondopening 401, and the third openings 403. In an embodiment the conductivematerial 701 may comprise copper, although other suitable materials,such as AlCu or Au, may alternatively be utilized. The conductivematerial 701 may be formed through a deposition process such aselectroplating or electroless plating, although other methods may suchas CVD or PVD may alternatively be utilized.

FIG. 8 illustrates a planarization process such as a chemical mechanicalpolishing (CMP) process that may be used to remove excess amounts of theconductive material 701 from those regions outside of the first opening217, the second opening 401, and the third openings 403 and form the PPI803. In an embodiment in which the planarization process is a CMP, acombination of etching materials and abrading materials are put intocontact with the conductive material 701 and a grinding pad 801 is usedto grind away the conductive material 701 until the conductive material701 is planarized with the third passivation layer 301.

After planarization, the PPI 803 and the third passivation layer 301 maybe cleaned in order to remove any undesired residue that may haveremained after the planarization process. In an embodiment the PPI 803and the third passivation layer 301 may be cleaned by rinsing the PPI803 and the passivation layer 301 with deionized water. Alternatively, aStandard Clean-1 (SC-1) or a Standard Clean-2 (SC-2) cleaning processmay be used. All such cleaning processes are fully intended to beincluded within the scope of the embodiments.

Once the PPI 803 and the third passivation layer 301 have been cleaned,the PPI 803 and the passivation layer 301 may be baked. In an embodimentthe PPI 803 and the third passivation layer 301 may be baked by placingthe substrate 101 along with the PPI 803 and the passivation layer 301into a furnace or other heating device (e.g., a hot plate) andincreasing the temperature of the third passivation layer 301 and thePPI 803 to a temperature of between about 150° C. and about 450° C.,such as about 200° C. The PPI 803 and the third passivation layer 301may be baked for a time of between about 5 min and about 240 min, suchas about 60 min.

By forming the PPI 803 as described herein, issues surrounding theformation of the PPI 803 may be reduced or eliminated. In particular, byusing these embodiments, an undercut issue between a seed layer and anoverlying electroplated layer that is usually present for fine pitches(e.g., less than about 5 μm) may be avoided, while also lowering costsand avoiding any loss of critical dimensions. Additionally, the seedlayer 601 in these embodiments is also located along the sidewalls ofthe PPI 803, and there is no depth bias associated with theseembodiments. Finally, as the PPI 803 in these embodiments have a cornerround profile, there is no crown issue as with some other processes.

FIG. 9 illustrates a placement of an external contact 901 along with athe placement of a buffer layer 903. In an embodiment the externalcontact 901 may comprise a material such as tin, or other suitablematerials, such as silver, lead-free tin, or copper. In an embodiment inwhich the external contact 901 is a tin solder bump, the externalcontact 901 may be formed by initially forming a layer of tin throughsuch commonly used methods such as evaporation, electroplating,printing, solder transfer, ball placement, etc., to a thickness of,e.g., about 100 μm. Once a layer of tin has been formed on thestructure, a reflow may be performed in order to shape the material intothe desired bump shape.

Once the external contact 901 has been placed and reflowed, the bufferlayer 903 may be placed or formed on the third passivation layer 301 inorder to protect and buffer the underlying structures. In an embodimentthe buffer layer 902 is a dielectric passivation material such assilicon dioxide, polyimide, or the like, that may be placed or formed,depending at least in part on the precise material chosen, using aprocess such as chemical vapor deposition, physical vapor deposition,spin-coating, or the like. The buffer layer 902 may be formed to athickness of between about 5 μm and about 200 μm, such as about 100 μm.

In accordance with an embodiment, a semiconductor device comprising apatterned positive tone photosensitive material over a substrate isprovided. The patterned positive tone photosensitive material comprisesopenings. A seed layer is along the openings and a conductive materialis adjacent to the seed layer.

In accordance with another embodiment, a semiconductor device comprisinga patterned negative tone photosensitive polyimide layer over asubstrate is provided. A patterned positive tone photosensitivepolyimide layer is over and in contact with the patterned negative tonephotosensitive polyimide layer, the patterned positive tonephotosensitive polyimide layer comprising at least one opening.

In accordance with yet another embodiment, a method of manufacturing asemiconductor device comprising placing a first photosensitive materialover a conductive region over a substrate is provided. The firstphotosensitive material is patterned to remove unexposed firstphotosensitive material and expose the conductive region. A secondphotosensitive material is placed over the first photosensitivematerial. The second photosensitive material is patterned to removeexposed second photosensitive material and expose the conductive region,the patterning the second photosensitive material forming a patternedsecond photosensitive material and at least one opening in the patternedsecond photosensitive material. A seed layer is formed along sidewallsof the at least one opening.

Although the present embodiments and their advantages have beendescribed in detail, it should be understood that various changes,substitutions and alterations can be made herein without departing fromthe spirit and scope of the embodiments as defined by the appendedclaims. For example, the precise shape of the first opening, the secondopening, and the third openings may be changed, or the precise methodsof formation may be altered. Additionally, any suitable number of masksfor the die, such as two masks, three masks, four masks, or any othersuitable number of masks, may be utilized.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure of the embodiments, processes, machines,manufacture, compositions of matter, means, methods, or steps, presentlyexisting or later to be developed, that perform substantially the samefunction or achieve substantially the same result as the correspondingembodiments described herein may be utilized according to theembodiments. Accordingly, the appended claims are intended to includewithin their scope such processes, machines, manufacture, compositionsof matter, means, methods, or steps.

What is claimed is:
 1. A semiconductor device comprising: a patternednegative tone photosensitive material over a substrate, the patternednegative tone photosensitive material comprising first openings; apatterned positive tone photosensitive material over the patternednegative tone photosensitive material, the patterned positive tonephotosensitive material comprising second openings, wherein thepatterned negative tone photosensitive material extends from a firstsidewall of a first one of the second openings to a second sidewall ofthe first one of the second openings; a seed layer extending alongsidewalls of the second openings; and a conductive material adjacent tothe seed layer.
 2. The semiconductor device of claim 1, wherein thepatterned negative tone photosensitive material comprises a negativetone photosensitive polyimide material.
 3. The semiconductor device ofclaim 1, wherein the patterned positive tone photosensitive materialcomprises a positive tone photosensitive polyimide material.
 4. Thesemiconductor device of claim 1, wherein the conductive material forms apost-passivation interconnect, wherein the post-passivation interconnectfurther comprises: a contact region; and routing lines laterallyseparated from the contact region.
 5. The semiconductor device of claim4, wherein the post-passivation interconnect has a pitch of less thanabout 5 μm.
 6. The semiconductor device of claim 1, wherein theconductive material is copper.
 7. A semiconductor device comprising: apatterned negative tone photosensitive polyimide layer over a substrate,the patterned negative tone photosensitive polyimide layer comprising atleast one first opening; and a patterned positive tone photosensitivepolyimide layer over and in contact with the patterned negative tonephotosensitive polyimide layer, the patterned positive tonephotosensitive polyimide layer comprising at least one second openingand at least one third opening, wherein the second opening is directlyover the first opening and the third opening extends through but notbeyond the patterned positive tone photosensitive polyimide layer. 8.The semiconductor device of claim 7, further comprising: a seed layerextending along sidewalls of the at least one opening; and conductivematerial filling a remainder of the at least one opening.
 9. Thesemiconductor device of claim 8, wherein the conductive material forms apost-passivation interconnect, wherein the post-passivation interconnectfurther comprises: a contact region; and routing lines laterallyseparated from the contact region.
 10. The semiconductor device of claim8, wherein the post-passivation interconnect has a pitch of less thanabout 5 μm.
 11. The semiconductor device of claim 7, wherein theconductive material is copper.
 12. A semiconductor device comprising: apatterned negative tone photosensitive polyimide layer over a substrate;substrate, wherein the patterned negative tone photosensitive polyimidelayer comprises a polymer based off of the following formula:

where X is a tetravalent organic group derived from alicyclictetracarboxylic acid dianhydrides having 3 to 30 carbon atoms; A₁ is anoxygen atom or an NH group; Y is a di-valent organic group derived fromaliphatic, alicyclic, or non-conjugated aromatic diamines with carbonatoms between 3 and 30, wherein side chains have one or moreethylenically unsaturated, cross-linkable bonds; and R₁ is a hydrogenatom or an organic group having 1 to 20 carbon atoms including one ormore ethylenically unsaturated bonds or is a group comprising aphotopolymerizable olefin double bond; a patterned positive tonephotosensitive polyimide layer over and in contact with the patternednegative tone photosensitive polyimide layer, the patterned positivetone photosensitive polyimide layer comprising at least one opening; aseed layer along the at least one opening; and a conductive materialadjacent to the seed layer.
 13. The semiconductor device of claim 12,wherein the conductive material forms a post-passivation interconnect.14. The semiconductor device of claim 13, wherein the post-passivationinterconnect comprises: a contact region; and conductive lines separatedfrom the contact region by the patterned positive tone photosensitivepolyimide layer.
 15. The semiconductor device of claim 14, furthercomprising an external contact in electrical connection with the contactregion.
 16. The semiconductor device of claim 15, further comprising abuffer layer adjacent to the external contact.
 17. The semiconductordevice of claim 13, wherein the post-passivation interconnect has apitch of less than about 5 μm.
 18. The semiconductor device of claim 12,wherein the conductive material has a top surface that is planar withthe patterned positive tone photosensitive polyimide layer.
 19. Thesemiconductor device of claim 12, wherein the conductive materialcomprises copper.